function Layer(path, handler) {
  this.path = path;
  this.handler = handler;
}
Layer.prototype.match = function (pathname) {
  // 路径匹配
  return this.path == pathname;
};
Layer.prototype.handle_request = function (req, res, next) {
  this.handler(req, res, next);
};

module.exports = Layer;

// Router外层中存放的是 layer (路径，dispatch)
// Route 是里层的 存放的是layer (不考虑路径， 用户真正执行的逻辑)
